The present invention generally relates to architectural lighting, and more particularly relates to luminaires that provide both direct and indirect lighting, so-called "direct-indirect" luminaires. The invention finds particular application in the field of linear fluorescent lighting where ambient light is produced from fluorescent lamps mounted in an elongated housing having a predetermined length and characteristic cross-sectional shape.
Linear direct-indirect lighting has been known for many years. Such fixtures normally provide indirect or "up" lighting through the top of the luminaire housing which is open (or is covered by a light transmitting element such as a lens cover), and a direct or "down" lighting component through one or more openings in the bottom of the housing, openings which are typically covered by lenses, baffles, or louvers to shield the luminaire's fluorescent lamps from direct view. Such shielding is desirable since exposure of the lighting emitting surfaces of the lamps within the luminaire through the direct light openings can produce uncomfortable visible brightness and distracting glare on work surfaces.
The disadvantage with existing direct-indirect lighting luminaires is that in many designs, the lamps are not adequately shielded from all viewing angles from below the luminaire leading to a condition where, at certain angles, the bright surfaces of the lamps project through the luminaire's down light openings with detrimental consequences to the lighting environment. In the present invention, the lamps of a direct-indirect luminaire are totally shielded from view through the fixture's down light openings regardless of the viewing angle. At the same time the amount of light available to the down light openings can be maximized.